Film thickness measuring method of member to be processed using emission spectroscopy and processing method of the member using the measuring method

A system comprising:

• a film thickness measuring apparatus for measuring a film thickness of a member to be processed, including:
• a differential waveform pattern data base for holding a standard pattern consisting of a time differential value of an interference light for each of multiple wavelengths with respect to a film thickness of a first member to be processed;
• a unit for measuring an intensity of an interference light for each of multiple wavelengths of a second member to be processed;
• a unit for obtaining a real pattern consisting of time differential values of measured interference light intensities;
• and
• a unit for obtaining a film thickness of said second member according to said standard pattern consisting of said time differential values and said real pattern consisting of said time differential values.